evinrude fastwin 18hp bogging

i had quite a lengthy post on the forum last year regarding this motor and getting it going after i bought it. It was running lean and wouldnt idle and i replaced just about everything ignition and fuel related including thermostat and head gasket. Finally took it to a marina and they adjusted timing and sealed up leaky welch plugs in carb and she runs like a champ...starts very easily...idles very well and runs at full throttle very well....only problem i have is going from a dead stop to full throttle...the motor bogs and takes some time to pick itself up. it's hard to describe beyond that, almost like it's running to rich and then finally leans back out and runs good. it only does it on acceleration from dead stop to full throttle when trying to get on plane to move fishing spots. the high speed jet is fixed in this carb and has a low speed adj but i hate to mess with that since it idles so well. it's a 1969, 18902b. i think i have a video clip of this i will try and post soon.

Re: evinrude fastwin 18hp bogging

heres the video

Re: evinrude fastwin 18hp bogging

I'd say it runs pretty darn good just like it is, however, it sounds like it's getting fuel a bit early. You could adjust it so that the throttle plate opens a tad later if you wanted. You could also widen the plug gaps just a bit as well.

Re: evinrude fastwin 18hp bogging

widening the plug gaps gives a hotter spark to burn the extra fuel? is that the thought behind that? wanna make sure im on the right track...i remember i gapped them to specs, what would you recommend opening them up too?

Re: evinrude fastwin 18hp bogging

Id say try n open idle adjustment screws a hair that may do it ??If not then open up plugs a hair ...see how it goes ... I thought it sounded pretty darn good also if this dont do it simpy turn screws back in worth a shot ...

Re: evinrude fastwin 18hp bogging

870 Expressmag said:

widening the plug gaps gives a hotter spark to burn the extra fuel? is that the thought behind that? wanna make sure im on the right track...i remember i gapped them to specs, what would you recommend opening them up too?

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When you twist the throttle you are doing two things: 1) open the throttle plate on the carb and 2) advance the spark timing. I think what oldcatamount is suggesting is to let the spark advance a bit more before the throttle plate on the carb opens up